This invention relates to a high-voltage electronic tube such as an X-ray tube of concentric construction, having a vacuumized housing comprising a cylindrical outer metal jacket, an annular ceramic insulating disc and a rod-like or tubular electrode support (guide) which passes centrally through the insulating disc into the jacket interior. A vacuumtight circumferential bond is provided between the outer circumference of the insulating disc and the inner face of the jacket as well as between the inner circumference of the insulating disc and the outer face of the electrode support. An X-ray tube of this type is disclosed, for example, in German Patent No. 2,448,497 and the June 1983 issue of an AEG Telefunken publication entitled "X-ray Tubes in the Metal-Ceramic Technology" (FIG. 3).
In electronic tubes of the above-outlined type it is a desideratum to further improve the high-voltage stability, to reduce the structural space of the tubes and to operate the tubes with increased voltages.